I am ridiculously excited for all of thi. I LOVE IA and ONE so much and was really hoping for updated song banks, and I will definitely be buying them...and potentially H as well. I'm very happy to see H alive again, if it is the same H. I was ridiculously excited for a third Aria because the two we have are already some of my all time favorites!
As for the sound of IA, I wouldn't mind if she sounded the same or different, though I am expecting a tone more similar to her English bank, with less engine.
Just a little speculation on my part, but I'm imagining she'll sound osmething like she does in
Pray For Real. It may be my ears playing tricks on me, but as someone wo owns both IA and IA English, the tones of theme are not similar enough for that smooth of a transition between the two languages. I'm guessing they either did some magic on Vocaloid IA (of which I found Rocks is more similar to ENglish, but still very different) or they used IA English for the Japanese, or something else entirely, I think it's a good measure for about how she'll sound. Or at least, how I'm expecting her to sound if she stays closer to her English tone.